Long-term results of cruciate-retaining total knee replacement in patients with rheumatoid arthritis: a minimum 15-year review.

Background: There is controversy about whether to retain or excise the posterior cruciate ligament in rheumatoid knees because attenuation of the ligament is often present in this subgroup of patients. We reviewed more than 15 years of results of cruciate-retaining total knee replacements (TKRs) in patients with rheumatoid arthritis.

Methods: We reviewed patients' charts and radiographs to evaluate knee range of motion and flexion contractures, component loosening and osteolysis at the bone-cement interface. Our primary outcome was revision of a femoral or tibial component for any reason, and the secondary outcome was revision for any reason and periprosthetic fracture during the follow-up period.

Results: Our study included 112 patients (7 men, 105 women, 176 knees). Their mean age was 49.3 (range 33-64) years. Twenty-one patients died and 16 were lost to follow-up, leaving 75 patients (119 knees) with a minimum follow-up of 15 (mean 16.1) years for our analysis. Of these, 61 patients (101 knees) were available for clinical and radiological evaluation at the final follow-up assessment. At a mean of 12.2 (range 6-16) years, revision was necessary in 14 patients (19 knees), including 1 patient with an infection. Eleven patients (11 knees) had periprosthetic fractures at a mean of 11.4 (range 5-14) years after the index operation. The survival rate, with the end point being revision of the femoral or tibial component for any reason, was 98.7% at 10 years and 83.6% at 17 years. The survival rate of revision and periprosthetic fracture was 97.6% at 10 years and 76.9% at 17 years.

Conclusion: Special attention should be paid to component loosening or periprosthetic fracture after more than 10 years of follow-up in this subgroup of patients.